Description: (Applicant's Description) The Flow Cytometry Core Facility at Moffitt Cancer Center provides a centralized service for Cancer Center members and University of South Florida faculty with cancer related research interests. Flow cytometry is a critical technical aspect of numerous Cancer Center projects due to its versatility and usefulness for rapid analysis of multiple characteristics on many cells, as well as for the identification of different cell types in mixed populations. Flow cytometry is a diverse analytical tool, which is crucial in the clinical and basic research pursuits to understand cancer biology and control. The Core provides the following services: single and multicolor fluorescence analysis, cell sorting, highspeed sorting, DNA content and cell cycle analysis, cytoplasmic calcium determinations, viability and apoptosis assessments, data analysis and graphics, training of investigators for data acquisition and analysis. The Facility provides expert technical consultation on experimental designs and trouble-shooting, sample acquisition and analysis. In 1999 the facility was utilized by 21 funded investigators (28 projects) which accounted for 87 percent of the total usage. Usage has increased steadily over the last several years and is projected to increase due to the addition of a high-speed sorter, recruitment of researchers who utilize flow cytometry, and the addition of a staff scientist within the Core. The funds requested from the CCSG will support a portion of two FTEs and 40 percent of the instrument service contracts. The total operating cost of this facility is $210,462. We are requesting $75,396 from the CCSG allocation, an amount that represents approximately 36 percent of the total operating budget.